Up to you, as said.. cars are about the same except the suspension.
Since this is your dream, what is your final plan for the car? Stock, street monster, drag, auto-x, roado course? Any plans for an extended warranty?
Stock and or warranty... depending on the price and milage, get the 13 and upgrade the suspension.
If you are going to mod it, and if you are hanging out here you will, get the 15 unless there is very little difference in the milage.
My plan was to stay stock, but 4K miles into it and everything I read here... well, it's in my sig
Either way, what ever makes more sense to you and your financial situation. 13, 15, you will be beyond happy either way which is all that counts.
Congrats, welcome and enjoy!!!
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PERFORMANCE: ColdAirInductions CAI, ADM Race Scoop, Cordes Performance Racing Ported TB/IM/Custom VVT Cam, WFO Milled Heads, Stainless Power 1 7/8" LT/3" HFCs, JBA 3" Comp. Cat-Back, Taylor 10.4mm Plug Wires, Tim King Performance Stage 3 6L80, Circle D Billet 3600 Stall, Nic D ECM/TCM Tune, - 458rwhp/413rwtq (prior to PIM), Forgestar F14 (F)18" / (R)17" Rims.
SUSPENSION: Z/28 Rear UCA Bushings, Carlyle Racing LCA/TA, BMR Adj. Toe Rods/Xtreme Anti-Roll Bar, Justice Pete Castor Locks/Radius Rod Inserts, Pegasus Billet Rear Cradle Bushings, Mickey Thompson Street SS II 305/45/17 tires.